The objective of this program is the total, non-enzymic synthesis of naturally occurring ribonucleic acids (RNA) having important identifiable functions, including phenylalanine transfer-RNA (t-RNA Phe) and, as a longer range goal, a biologically replicating RNA of the viroid type. In reaching these ends, there will be utilized a combination of relay chemistry, involving t-RNA Phe as the starting material, and normal, non-enzymic synthesis of oligonucleotides also attained by t-RNA degradation. In both connections, attempts will be made to develop new reaction pathways, and synthetic approaches useful for nucleotide construction.